Computational Complexity and other fun stuff in math and computer science from Lance Fortnow and Bill Gasarch

Thursday, December 23, 2004

FSTTCS 2004 at Chennai

By Prahladh Harsha and Jaikumar Radhakrishnan

It was nice to be back in Madras after a long time and even nicer
to meet friends from MIT and elsewhere during this year's Foundations
of Software Technology and Theoretical Computer Science Conference.
FSTTCS is the longest-running international conference on computer
science in India, and is organized under the aegis of the Indian Association for Research in
Computing Science (IARCS).

The 24th edition was held
in Chennai between Dec 16 and Dec 18. The conference was preceded by
two workshops on Algorithms for dynamic data (Dec 13 - 14) and Logics
for dynamic data (Dec 15). Here are a few statistics about this
year's FSTTCS: 38 accepted papers (out of 178 submitted from 38
countries), attendance of about 175 (nearly 35% from outside
India). The invited speakers: Pavel Pevzner (UCSD), Javier Esparza
(Stuttgart), Piotr Indyk (MIT), John Reynolds (CMU) and Denis Therien
(McGill). The proceedings of the conference were published by
Springer in LNCS series.

FSTTCS attracts papers in Logics &amp Semantics and Algorithms &amp
Complexity. Biased by our interests, we attended only the
presentations on Algorithms &amp Complexity. In our view, the
highlights were:

M Fürer, S P Kasiviswanathan, An almost linear time approximation
algorithm for the permanent of a random (0-1) matrix.

L Radamacher, S Vempala, Testing geometric
convexity. This paper demonstrates that testing whether a given
set S in R^n is convex or far from convex (in the property-testing
sense) can be determined by queries, whose number is independent of
the actual size of the set S, but is however exponential in the
dimension of the space (i.e., n). The set S is presented to the tester
by a membership oracle and a random oracle.

J Hitchcock, A Pavan, Hardness hypotheses, derandomization
and circuit complexity. This paper shows that the NP-machine
hypothesis is implied by both the Measure hypothesis and pseudo-NP
hypothesis. These 3 hypotheses are some of the commonly used
hypotheses in derandomization. Furthermore, the authors show that
several of the derandomization and circuit lower-bound results that
are known to follow from the latter two hypotheses also follow from
the NP-machine hypothesis.

J Kempe, A Kitaev, O Regev, The complexity of the local
Hamiltonian problem. The local Hamiltonian problem is a natural
complete problem for the complexity class QMA, the quantum analog of
NP. It was known that the 1-local Hamiltonian problem is in P while
the k-local Hamiltonian problem is QMA-complete for k &gt= 3. This paper
settles the case for the 2-local Hamiltonian problem and shows that it
is also QMA-complete. Thus, the k-local Hamiltonian problem is similar
in spirit to MAX-k-SAT which is NP-complete for k &gt = 2.

Some authors could not attend the conference. The paper Minimum
weight pseudo-triangulations by J Gudmundsson and C Levcopolous
was presented beautifully by Mark de Berg. The paper on No,
coreset, no cry by S Har-Peled, was presented by Kasturi
Varadarajan. The author did
not get a visa in time from the Chicago consulate (there are some
advantages to traveling on an Indian passport), and had sent a
recording of his presentation. In the end, Kasturi did a wonderful job
using only the slides, but one was left wondering what the video
looked like.

Prof. Rani Sirmoney, who turned 75 in July 2004, was honored in a
special session at the conference. Prof. Sirmoney is a senior and
highly respected theoretical computer scientists in India who works in
the area of Formal Languages, Automata Theory, Machine Learning and
DNA Computing. She has nurtured several generations of researchers
through her teaching and collaborations. In her speech, she thanked
her colleagues at the Madras Christian College for their support and
encouragement, and mentioned, among other things, that she never faced
any gender-based discrimination at that institution.